Each book is 2.4cm thick; that means if you're stacking books on top of each other, that is, on their sides, each book will be 2.4 cm tall. multiply the length of each book (2.4cm) by 21 to figure out how tall 21 books together will be. 2.4 x 21 = 50.4. the shelf needs to be at least 50.4cm tall.
Answer:
9*((2-1)/9)
or
<u>2</u><u> </u><u>-</u>1
9
<u>2-9</u><u> </u>=<u>-7</u>
9. 9
9× <u>-7</u>
9
=<u>-7</u>
<u>2-</u> <u>3</u>
9. -3
=(1.22222222222)
or
11/9
or
1*(2/9)
Can you add the whole question I think it may be 6/4
